The category page shows the latest stories in the selected category. You can go to the Home page by clicking the ThinkProgress logo. You can choose other categories and customize the categories that appear along the bottom of the screen by clicking the More button.
The story page shows the full text of the story and associated videos and pictures. (Some video may be incompatible with the iPhone.) You can also share the story via Facebook, Twitter, Email, and SMS. Sharing via Facebook or Twitter require you to authorize the App to work with your accounts. Data and text rates may apply.